J/MNRAS/413/1515 New grids of Atlas9 models (Howarth, 2011)
New limb-darkening coefficients and synthetic photometry for model-atmosphere
grids at Galactic, LMC, and SMC abundances.
Howarth I.D.
<Mon. Not. R. Astron. Soc. 413, 1515 (2011)>
=2011MNRAS.413.1515H 2011MNRAS.413.1515H
ADC_Keywords: Models, atmosphere
Keywords: stars: atmospheres - binaries: eclipsing - planetary systems
Abstract:
New grids of Atlas9 models have been calculated using revised
convection parameters and updated opacity-distribution functions,
for chemical compositions intended to be representative of solar,
[M/H]=+0.3,+0.5, Large Magellanic Cloud (LMC), and Small Magellanic
Cloud (SMC) abundances. The grids cover Teff=3.5-50kK, from logg=5.0
to the effective Eddington limit. Limb-darkening coefficients and
synthetic photometry are presented in the UBVRIJHKLM, uvby, ugriz,
WFCAM, Hipparcos/Tycho, and Kepler passbands for these models, and for
Castelli's comparable 'new-ODF' grids. Flux distributions are
given for the new models. The sensitivity of limb-darkening
coefficients to the adopted physics is illustrated.
Description:
The "Atlas9.C04" directory contains grids of products newly generated
from the atmospheric structures provided by Castelli & Kurucz (2004,
IAUS, 203, p. A20; 0405087). Subdirectories have names
of the form, e.g., "m20v02" or "p05av02", where
M20V02 MEANS [m/h] = -2.0, v(turb) = 2 km/s
p05av02 means [M/H] = +0.5, alpha elements enhanced, v(turb) = 2 km/s
The Atlas9.C04 models use Grevesse & Sauval (1998SSRv...85..161G 1998SSRv...85..161G)
solar abundances, and mixing-length parameter l/H=1.25
The "Atlas9.A10" directory contains grids of products from newly
calculated structures. Subdirectory naming mirrors that in
Atlas9.C04.
The models are based on Asplund et al. (2005ASPC..336...25A 2005ASPC..336...25A) solar
abundances, and mixing-length parameter l/H=1.25; subdirectories
suffixed "r" are for models with l/H=0.5. Model grids at notionally
LMC and SMC abundances are included.
Within each grid subdirectory there are three plain-text files for
each model, with names of the form 't05000g40.', where the base
identifies the effective temperature and log(g), and the extension
identifies the file content.
Files with '.flx' extensions contain listings of physical fluxes at
1221 wavelengths, from 90 angstrom to 160 micron (with 20-angstrom
sampling through the optical). Fluxes are tabulated in erg/cm2/s/Å
as a function of wavelength (in angstrom).
Limb-darkening coefficients are provided in files with extensions
'.ucP' (for photon-counting detectors) and '.ucE' (for
energy-integrating detectors).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 64 32 Summary of Atlas9 models
models.dat 56 15144 List of files and related parameters
C04/*/*.flx . 8568 Physical fluxes files in C04 grids
A10/*/*.flx . 6576 Physical fluxes files in A10 grids
C04/*/*.uc* . 17136 Limb-darkening coefficients in C04 grids
A10/*/*.uc* . 13152 Limb-darkening coefficients in A10 grids
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- --- [Atlas9.]
8- 10 A3 --- Src Structure source (A10 or C04)
12- 18 A7 --- Grid Grid name (includes metallicity/ξ)
20- 23 F4.2 --- l/H Ratio of mixing length to pressure scale height
25- 27 I3 --- N Number of models in a given grid (G1)
29- 32 A4 --- [M/H] Metallicity (including LMC and SMC)
34- 36 F3.1 km/s xi Turbulent velocity ξ
38- 42 A5 --- alpha [alpha] indicates α-elements enhanced
44- 47 I4 K Tmin ? Lower value for temperature interval
48 A1 --- --- [-]
49- 53 I5 K Tmax Upper value for temperature interval
55- 57 F3.1 [cm/s2] gmin ? Lower value for surface gravity interval
58 A1 --- --- [-]
59- 61 F3.1 [cm/s2] gmax Upper value for surface gravity interval
63- 64 I2 --- Ng Number of different logg values
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Byte-by-byte Description of file: models.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- --- [Atlas9.]
8- 28 A21 --- File File name, without extension (G1)
30- 33 F4.2 --- l/H Ratio of mixing length to pressure scale height
35 A1 --- n_[M/H] [LS] Large/Small Magellanic Cloud metallicity
36- 39 F4.1 --- [M/H] [-4/0.5]? Metallicity
(if blank, specified in n_[M/H])
42- 44 F3.1 km/s xi Turbulent velocity ξ
46 A1 --- a [a] indicates α-elements enhanced
48- 52 I5 K Teff [3500/50000] Effective temperature
54- 56 F3.1 [cm/s2] logg [0/5] Surface gravity
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Byte-by-byte Description of file: C04/*/*.flx A10/*/*.flx
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Bytes Format Units Label Explanations
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3- 15 E13.8 0.1nm lambda Wavelength (90Å to 160µm)
18- 30 E13.8 10mW/m2/nm Flux Flux (in erg/cm2/s/Å)
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Global Notes:
Note (G1): Each grid contains files named "tNNNNNgNN.flx", "tNNNNNgNN.ucE",
"tNNNNNgNN.ucP", where "tNNNNN" is the effective temperature in K,
(3500K≤Teff≤50000K), and "gNN" is the surface gravity in dex,
(0≤logg≤5.0)
* Files with '.flx' extensions contain listings of physical fluxes at
1221 wavelengths, from 90Å to 160um (with 20-Å sampling through
the optical).
* Files with '.ucP' extensions contain limb-darkening coefficient for
photon-counting detectors
* Files with '.ucE' extensions contain Limb-darkening coefficient for
energy-integrating detectors
--------------------------------------------------------------------------------
Description of file: for .ucP and .ucE files
Broad-band limb-darkening coefficients are in the following format,
illustrated by V-band results for the 9.55kK Vega model:
Bessell-V 5467.7 5.61840E+07 2.08372E+07 -0.207
4-coeff +4.73679E-01 +5.53030E-01 ... ... +2.75266E-04 -7.09332E-04
quadratic +2.25617E-01 +3.71954E-01 +1.56919E-02 -4.19850E-02
quad - FC +2.74255E-01 +3.01889E-01 +1.82965E-02 -6.25047E-02
square root +2.25306E-02 +6.82355E-01 +2.77154E-03 +6.52661E-03
logarithmic +6.36370E-01 +3.25055E-01 +5.45636E-03 -1.48612E-02
linear - 2 +1.04831E+00 +5.92481E-01 +3.77170E-02 -9.16531E-02
linear - 1 +5.25808E-01 +4.55362E-02 -1.09348E-01
linear - FC +4.25199E-01 +7.68496E-02 -2.08951E-01
Here the first line lists
(i) the passband,
(ii) the effective wavelength (in angstrom),
(iii) the broad-band physical flux (in erg/cm2/s/A),
(iv) the broad-band surface-normal intensity (in erg/cm2/s/A/sr), and
(v) the bolometric correction (for Johnson passbands only).
Subsequent lines list coefficients for various limb-darkening laws
(see paper for details). The final two numbers in each row are the
r.m.s. and maximum differences between input and modelled values of
I(mu)/I(1).
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Acknowledgements:
Ian Howarth, idh(at)star.ucl.ac.uk
(End) Patricia Vannier [CDS] 02-Dec-2010